<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        //打印五行五列星星
        var str = '';
        for(var i = 1;i <= 5;i++){  //外层循环负责打印五行
            for(var j = 1;j <= 5;j++){ //里层循环负责打印一行五颗星星
                str = str + '★';
            }
            //如果一行打印完毕5个星星就要另起一行 加 \n
            str = str + '\n';
        }
        console.log(str);
    </script>
</head>
<body>
    
</body>
</html>